Comparison of Routine and Concentration Techniques on Microscopic Examination of Stool for Parasitic Ova & Cysts

Abstract

Objective: To compare the routine and concentration techniques on microscopic examination of stool for
parasitic ova and cysts to emphasize importance of concentration technique
Methods: A descriptive study of 100 symptomatic and asymptomatic patients who attended the Microbiology
Lab, Pathology Department, Family Hospital, Rawalpindi a teaching hospital affiliated with Rawalpindi Medical
College were studied for six months for stool examination. Three samples from each case at three different days
were selected not necessarily consecutive. Three techniques were applied on all samples which included direct
microscopic examination by using saline and iodine preparations and the microscopic examination after using
two concentration techniques which included simple salt flotation technique and Formal-ether concentration
technique.
Results: In routine technique 4% of patients were positive for ova/cysts. In saturated saline floatation technique
8% of patients were positive for ova/cysts of parasites. In formal ether sedimentation technique also 8%of
patients were positive.
Conclusion: Concentration techniques (formal-ether sedimentation and saturated salt floatation) significantly
improved the sensitivity from 4% to 8% for detection of ova/cysts of parasites as compared to routine iodine
preparation technique. Although concentration techniques are well known, these need to be implemented in
those laboratories where these are not used.